CVE-2021-42761 Explained : Impact and Mitigation

A session fixation vulnerability in FortiWeb versions 6.4, 6.3, 6.2, 6.1, 6.0, and 5.9 could allow unauthorized users to compromise sessions.

Understanding CVE-2021-42761

What is CVE-2021-42761?

A session fixation vulnerability in FortiWeb versions 6.4, 6.3, 6.2, 6.1, 6.0, and 5.9 may permit remote attackers to hijack users' sessions by inferring session identifiers.

The Impact of CVE-2021-42761

This vulnerability could result in unauthorized access to other users' sessions, potentially leading to data theft or misuse.

Technical Details of CVE-2021-42761

Vulnerability Description

The vulnerability involves improper session management in FortiWeb versions, allowing malicious actors to exploit session identifiers of other users.

Affected Systems and Versions

Versions 6.4, 6.3, 6.2, 6.1, 6.0, and 5.9
Specific affected versions listed in JSON data.

Exploitation Mechanism

Remote, unauthenticated attackers exploit session fixation vulnerability to infer and take over other users' sessions.

Mitigation and Prevention

Immediate Steps to Take

Upgrade to FortiWeb version 7.0.0 or higher.
Upgrade to FortiWeb versions 6.3.17, 6.2.7, 6.1.3, 6.0.8, or 5.9.2 as recommended.

Long-Term Security Practices

Implement strong session management practices.
Regularly monitor and audit session activities.
Educate users on session security best practices.
Keep systems up to date with the latest patches and updates.